mericon Sample Preparation Kits

For extraction of high-quality DNA from microbial enrichment cultures and raw or processed foods

Modified CTAB procedure ensures faster sample processing

Efficient isolation of even fragmented DNA from processed foods

Fast and efficient lysis of Gram-negative and Gram-positive bacteria

No carryover of PCR inhibitors from complex food matrices

mericon Sample Preparation Kits are designed to enable the extraction of high-quality nucleic acids from a wide range of starting materials, such as pathogen enrichment cultures (mericon DNA Bacteria and Bacteria Plus Kits) and a variety of raw and processed foods (DNeasy mericon Food Kit). The carryover of PCR inhibitors from these complex food matrices is minimized. The isolated, pure DNA is suitable for downstream applications, such as real-time PCR ingredient authentication, pathogen detection, or GMO DNA detection and quantification using mericon PCR Assay Kits.

mericon Sample Preparation Kits are intended for molecular biology applications in food, animal feed, and pharmaceutical product testing. These products are not intended for the diagnosis, prevention, or treatment of a disease.

mericon DNA Bacteria Kit.

mericon DNA Bacteria Plus Kit.

Performance

DNeasy mericon Food Kit

During production, food is subjected to heat, irradiation, high pressure, and changes in pH which lead to DNA degradation and fragmentation. The optimized chemistry of the DNeasy mericon Food Kit was developed to recover short DNA fragments (down to 100 bp) ensuring that even highly fragmented DNA is efficiently isolated and subsequently amplified in PCR reactions. Thanks to these features, this kit offers a universally applicable extraction method that generates optimal and reliable results with even highly processed, fatty, or acidic foods, or foods with high or low DNA contents or high inhibitor contents (see the figures "High yields of DNA with minimal inhibitor carryover").

mericon DNA Bacteria and DNA Bacteria Plus Kits

The thermal lysis protocol of the mericon DNA Bacteria Kit and the mechanical lysis protocol of the mericon DNA Bacteria Plus Kit are similarly efficient for the extraction of DNA from Gram-negative bacteria, while the mechanical lysis protocol is more effective for the extraction of DNA from Gram-positive bacteria (see the figure "Efficient bacterial DNA extraction").

Principle

DNeasy mericon Food Kit

This kit uses an improved cetyltrimethylammonium bromide (CTAB) extraction of total cellular nucleic acids. The nonionic detergent CTAB is widely used for efficient extraction of total cellular nucleic acids from a wide range of tissue types. Depending on the salt conditions, CTAB may complex with cellular nucleic acids (low-salt conditions) or complex with cellular inhibitors, such as polysaccharides, proteins, and plant metabolites (high-salt conditions; as found in the Food Lysis Buffer).

With fewer workflow steps than conventional CTAB protocols, up to 30 samples can be processed in 2.5 hours with the DNeasy mericon Food Kit (see the figure "Efficient and rapid DNA extraction").

The optimized protocol uses CTAB in combination with Proteinase K to first digest compact tissue and then to subsequently precipitate proteins with simultaneous precipitation of other cellular and food-derived inhibitors.

Inhibitors are precipitated by centrifugation, while the extracted DNA remains in solution. In the subsequent chloroform extraction, any remaining CTAB-protein, CTAB-debris, or CTAB-polysaccharide complex not precipitated is removed together with other lipophilic inhibitors by extraction into the organic chloroform phase. Only the aqueous phase containing the DNA and significantly depleted inhibitors is processed further. This phase is mixed with binding buffer (to adjust binding conditions) and applied to the QIAquick Spin Columns. The resulting DNA is immediately ready for use in a downstream mericon real-time PCR assay.

mericon DNA Bacteria Kit and mericon DNA Bacteria Plus Kit

To date, the predominant method to test food for the presence of pathogens has been via culture preparation and/or ELISA-based assays. Molecular-based methods, specifically real-time PCR, offer an informative complement to these well-established methods.

The thermal lysis protocol of the mericon DNA Bacteria Kit is optimized for the majority of easily lysed Gram-negative bacteria (e.g., Salmonella spp., Camplylobacter spp., and Cronobacter spp.). The mechanical lysis protocol of the mericon DNA Bacteria Plus Kit creates the appropriate conditions for bacterial extraction from Gram-positive bacteria, such as Listeria spp.

The carefully formulated chemistry included in the mericon DNA Bacteria Kit and the mericon DNA Bacteria Plus Kit maximizes lysis efficiency, stabilizes the extracted DNA, and removes inhibitors that may interfere with downstream applications.

Procedure

DNeasy mericon Food Kit

DNA is extracted from a homogenized food sample using a straightforward protocol that removes inhibitors and yields pure DNA that is suitable for downstream applications, such as real-time PCR ingredient authentication or GMO detection.

mericon DNA Bacteria Kit and mericon DNA Bacteria Plus Kit

Bacterial DNA is extracted from a bacterial enrichment culture using a protocol based on mechanical lysis (using beads) or thermal lysis (by boiling). Both protocols deliver a bacterial DNA suspension suitable for real-time PCR pathogen detection.

Applications

The DNeasy mericon Food Kit is for isolation of DNA from raw or processed foods for downstream applications, such as ingredient authentication.

mericon Bacteria and Bacteria Plus Kits are for the isolation of bacterial DNA from enrichment cultures of food and animal feed.